A significant shortcoming of previous HIV research is that it has polarized "heterosexual" transmission and "homosexual" without investigating the potentially substantial overlap between these routes through individuals who engage in "bisexual" behaviors. Limited research focusing directly on bisexual men has highlighted unique HIV risk factors and prevention needs. However, little information is available on how factors associated with bisexual men's risk behavior may be amenable to change through intervention. Using multiple methods, this development research study aims to: 1. identify the individual and socio- cultural determinants related to the sexual interactions that increase risk of HIV acquisition in a diverse sample of bisexual men in an underserved area of the Midwestern United States;2. evaluate the feasibility of engaging a diverse sample of bisexual men, in terms of recruitment and participation, in a multi-method study aimed at understanding the levels of risk to sexual health in order to inform a subsequent sexual health intervention;and 3. acquire information useful for designing relevant, accessible, and culturally-appropriate HIV/STI prevention information to be used in a subsequent intervention aimed at promoting sexual health among bisexual men. Using a community-informed research approach, in-depth interviews, and STI diagnostics from a diverse sample of 75 bisexual men, this study will provide rich insights into the individual and social-cultural factors, as well as the sexual and risk-related decision-making processes, that may be potential points of future sexual health promotion efforts. PUBLIC HEALTH RELEVANCE: This study will provide current data designed to develop and test a targeted sexual health intervention among bisexual men, a high risk population for HIV infection and transmission. Scientific outcomes will add to the knowledge base that is lacking evidenced-based information on the social, sexual, and risk behaviors of diverse groups of bisexual men. By improving our understanding of this previously understudied population, results will not only inform future research and intervention efforts but also be of benefit to bisexual men and their communities.